Bulletin of Environmental Contamination and Toxicology最新文献

This study aimed to assess the environmental and health risks of heavy metal contamination from e-waste recycling in Lahore, Pakistan. Surface soil (0-15 cm) samples were collected from recycling facilities, and heavy metal concentrations were measured using atomic absorption spectrophotometry. The mean concentrations (mg/kg) of Cadmium (Cd) (5.38), Copper (Cu) (835.53), Lead (Pb) (468.90), Mercury (Hg) (1.61), and Zinc (Zn) (416.39) exceeded European Union (EU) guidelines, while Manganese (Mn) (372.29), Iron (Fe) (750.05), Arsenic (As) (6.96) and Chromium (Cr) (64.80) were within limits. Soil contamination indices indicated soil quality deterioration. The highest ecological risks (Er) were from Cd (1646.232) and Hg (322.15). Children faced higher non-carcinogenic risk (2.93) and carcinogenic risk (1.76 × 10⁻³), particularly from Pb (1.74) and Cu (1.56 × 10⁻³), respectively, while adults faced no significant risks. These findings highlight the need for sustainable e-waste management practices in Pakistan.

Urban brownfields are abandoned industrial areas. They are generated as a result of land use transition in areas of rapid economic development within the urban context and are commonly contaminated with heavy metals and/or organics. Heavy metals lead to environmental degradation and functional degradation of the soil, thereby threatening the entire ecosystem. This work investigated the occurrence, sources, and risks of five target heavy metals in the old industrial city (Plots A, B, and C) of Wuhan. The heavy metal concentrations ranged from 0.02 to 253.00 mg/kg, and the dominant heavy metals were Hg, Pb, and Cu. Traffic emission/coal combustion and industry/natural/agricultural activities were identified as the main sources by the positive matrix factorization (PMF) model. The pollution load index (PLI), the potential ecological risk index (RI), and the geo-accumulation index (I_geo) results showed that Plot A had the highest soil risk, followed by Plots B and C. The carcinogenic effects on some sites of Plot A need to be considered. This work provides a theoretical basis for the assessment of heavy metal pollution and helps local governments to redevelop brownfields.

This study examines the impact of electromagnetic fields (EMF) on zebrafish (Danio rerio) sex ratio, survival, and organ health. Embryos were exposed to static EMFs for 63 days post-hatching across five aquariums, with varying intensities based on distance (30-99 cm). The control group remained EMF-free. The strongest exposure (30 cm) led to 100% feminization (p < 0.001), with all exposed groups showing significant deviations from the expected 1:1 sex ratio. Survival rates dropped below 35% in EMF-exposed groups, compared to 82.5% in controls. Histological analysis revealed gonadal abnormalities, necrosis, and liver degeneration in exposed fish. These findings provide the first documented evidence that EMF exposure disrupts sex ratios and health in fish, potentially affecting population stability in aquatic ecosystems. The predominance of females suggests long-term ecological consequences that could impact biodiversity in both aquatic and terrestrial environments.

Drinking water treatment residuals (DWTRs) are waste products generated during drinking water treatment. DWTR composition is typically dominated by either aluminum (Al), calcium (Ca), or iron (Fe) compounds, depending on the coagulant used at the source facility. Most commonly disposed of via landfill, the beneficial reuse of DWTRs as soil amendments and construction materials is desired yet complicated by the potential presence of contaminants, including microplastics (MPs). Currently, very little data is available on the occurrence of MPs in DWTRs, creating uncertainty regarding the potential reuse of this material. Here, the MP concentration in representative Al, Ca, and Fe DWTRs was determined by a two-part oxidation and density separation method to extract MPs for quantification via fluorescent staining. MPs were detected in all three DWTRs examined, with Ca DWTR containing the smallest number of MPs and Al DWTRs containing the larger number of MPs, suggesting that Ca DWTRs may be the freest of concerns regarding MPs contamination among DWTR types.

Particulate Matter (PM) pollution poses significant risks to human health and the environment, necessitating effective reduction strategies. The effects have been more evident in the industrial belts and areas in its vicinity. Vegetation, particularly leaves, have been recognized as a natural filter capable of trapping airborne pollutants like PM in these areas. The present study explores the ability of different plant species in Rourkela to capture PM of varying size fractions from air. The amount of PM₁₀ and PM_2.5 deposited on the foliar surfaces and trapped in epicuticular waxes of plant species were segregated and quantified by separate gravimetric analyses, from three different sites in Rourkela, and over three different seasons. Plants of all species were found to accumulate PM of large and coarse fraction sizes efficiently. Depending on the location and season, it was found that the quantities of foliar and in-wax PM varied among the studied plant species. Among the three seasons, the highest amount of PM accumulated by the plant species was recorded in the winter season measuring 90.102 × 10^- 4 g/cm². Furthermore, locational analysis of PM load identified site A to be the most PM polluted region followed by site B and site C. Overall, this research identifies plant species like Senna siamea, Thevetia peruviana and Alstonia scholaris that can efficiently accumulate both PM₁₀ and PM_2.5 and can be utilized for phytoremediation by developing a "Green Belt" in the PM polluted areas.

The bioaccumulation of trace elements (TEs) in the soft tissue of the clam Larkinia grandis from the Gulf of California (GC) and the risk of its consumption are still unknown. We evaluated the levels of aluminum (Al), arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), lead (Pb), and zinc (Zn) in the digestive gland, mantle, gills, gonad, and adductor muscle of L. grandis from the southeastern GC, collected bimonthly from August 2017 to June 2018. The concentrations of the studied elements (mg kg^-1 wet weight) presented the following decreasing order of abundance: Fe (62.7 ± 48.6) > Al (22.1 ± 13.5) > Zn (12.1 ± 1.4) > Cu (7.4 ± 1.5) ≥ As (6.9 ± 2.1) > Mn (2.6 ± 1.9) ≥ Cd (2.5 ± 1.1) > Pb (1.4 ± 0.4). Clam shell length and total weight were correlated with Cu concentrations in the digestive gland and gills (r = 0.95 and 0.92; r = 0.94 and 0.90, respectively) and Fe concentrations in the digestive gland (r = 0.97 and 0.91) (p < 0.05). Cadmium and Pb concentrations exceeded the maximum permissible limits established by the Mexican Official Standard (NOM-242-SSA1-2009) for safe human consumption. However, the human health risk assessment indices associated with clam consumption were low (Target Hazard Quotient and Hazard Index < 1). Due to the constant anthropogenic input in the region, continued research to more accurately assess the bioaccumulation dynamics of TEs in this clam and their relationship to the risk to human health from its consumption is a priority.

Landfill mining (LFM) is increasingly adopted in India as a strategy to reclaim land and recover materials from legacy municipal solid waste (MSW) dumpsites. The study evaluates the contamination levels of soil-like material (SLM: < 4.75 mm fine fraction) recovered from the Anantapur dump yard in South India, with the aim of evaluating its potential for reuse potential and environmental risks. Samples were analysed for organic content, total soluble solids, leachate characteristics, and heavy metal concentrations, using pollution indices such as the contamination Factor (C_f), geo-accumulation index (I_geo), and enrichment factor (EF) were applied to determine contamination severity. The organic content in SLM ranged from 14-17%, significantly exceeding typical thresholds for engineering reuse. Total soluble solids (800-1000 mg/L) and leachate sulphate and chloride concentrations, surpassed national water quality standards. Heavy metals such as lead and copper exhibited extreme contamination, while zinc and manganese show moderate to high contamination. The findings highlight that while landfill mining aids in waste reduction and land reclamation, the high contamination levels in SLM necessitate proper remediation before reuse. The findings contribute to growing knowledge on LFM and provide site-specific data critical for sustainable landfill reclamation in semi-arid regions.

Lower-tier toxicity assessments of chemicals, such as metals and pesticides, are typically focused on a few standard test species representing different taxonomic levels. Invertebrate taxa most frequently used are the crustacean and insect larvae. In recent years, some species of Oligochaeta have received increasing attention as test organisms, although the number of taxa evaluated so far is still limited. In previous studies, we successfully used the indigenous tropical oligochaete Allonais inaequalis to assess the acute toxicity of metals (cadmium, copper, mercury, and manganese) and pesticides (diuron and carbofuran). The aim of the present study was therefore to assess the sensitivity of this species to chronic (12d) exposure to these compounds. The order of chronic toxicity was the same as that denoted in the acute tests: copper (mortality 12d-EC10 2.22 µg Cu²⁺/L) > mercury (22.29 µg Hg²⁺/L) > cadmium (138.59 µg Cd²⁺/L) > manganese (5650 µg Mn²⁺/L) and carbofuran (46.32 µg/L) > diuron (6751.42 µg/L). Chronic toxicity did not increase significantly compared to the acute toxicity tests. Growth, measured as body length, was hindered after exposure to the metal and pesticides due to an energy reallocation needed to cope with the chemical stress.

Information about perfluoroalkyl substances (PFASs) like perfluoroalkyl carboxylic acids (PFCAs) and sulfonates (PFSs) in settled dust from emerging and developing countries is still limited, partly due to the lack of efficient analytical methods. In this study, a reliable, simple, and cost-effective analytical procedure was developed and validated to determine 12 PFCAs and 4 PFSs in dust samples. The samples were ultrasonicated with methanol, followed by a dispersive sorbent clean-up step with graphitized carbon and quantification by liquid chromatography with tandem mass spectrometry (LC-MS/MS) method. The analytical method exhibited adequate recovery (80-120% for native standards and 50-130% for labeled standards), precision (relative standard deviations < 25%), and detection limits (0.010-0.10 ng/g). The validated method was applied to analyze PFAS concentrations in settled dusts collected from Hanoi, Vietnam. PFASs were frequently detected in the Vietnamese dust samples at relatively low concentrations (median 4.15, max 27.4 ng/g).